Periodic Reporting for period 1 - STOP (Surface Transfer of Pathogens)
Berichtszeitraum: 2022-09-01 bis 2024-02-29
The aim of the STOP project is to develop materials that will help to reduce the spread of infection between people via surfaces – for example when somebody sneezes in a bus, the aerosol particles can settle on a surface such as a handrail, a second person may then grip that handrail and later use their contaminated hand to rub their eye or whilst eating a snack and thus become exposed to the infectious pathogen. The STOP project will develop antimicrobial and antiviral nanocoatings that can be flexibly or permanently applied to high-touch surfaces. These nanocoatings will be derived from a combination of inorganic nanoparticles, antimicrobial peptides and nanoscale laser surface patterning. The nanocoatings will be thoroughly characterised for their efficacy, using both existing international standards and improved testing methods developed within the project (the new testing methods will be proposed to standards agencies for adoption). Several different active substances will be explored (i) to allow formulation in highly flexible, sprayable, and long-lasting coatings, (ii) provide broad spectrum antimicrobial antiviral activity, and iii) reduce the chances of the development of resistance. To this end, the mode-of-action, and the risk of selection for antimicrobial resistance in bacteria and viruses will be assessed. The flexible nanocoatings will provide a long-lasting (30 days) reduction in bioburden that resembles standards set for microbial colonization of surfaces in hospitals, which can only be reached after intense surface disinfection or permanent introduction of known antimicrobial material such as copper. This effect will be studied in a real-life intervention trail and with epidemiological models. The developed nanocoatings are expected to lead to significant reductions in infectious diseases transmitted from high-touch surfaces, healthcare cost savings, reduction in environmental pollution by disinfectants, and increased preparedness of the EU public health system to future pandemics. The safety of the nanomaterials will be backed up by human and environmental toxicity studies and life cycle analyses. From the beginning, attention will be paid to end-user acceptance, manufacturing scalability, and short-term exploitation by SMEs.
In the first 18 months of the project over 120 novel surfaces have been created and screened for antibacterial or antifouling activity. (Since the aim of the project is to prevent the transfer of pathogens between people via surfaces, a surface to which no pathogens can stick is just as effective as a surface that kills pathogens). These surfaces (on metal, plastic or glass) were created either by laser texturing, or the deposition of specially functionalised nanoparticles or polymers, or a combination of both. Antifouling properties are achieved by adjusting the nanoscale surface roughness to get something similar to the well-known ‘lotus effect’, in other words a superhydrophobic surface which is not wetted by water droplets. Bacterial killing properties can be obtained by using synthetic peptides (small protein chains) that mimic the properties of materials found in nature.
The project has confirmed (and in some cases begun to optimize) the antimicrobial activity of a number of types of nanocoating, including those exploiting the photocatalytic behaviour of titanium dioxide, the use of synthetic antimicrobial peptides attached to mesoporous silica nanoparticles, the use of metal particles (silver or copper) surrounded by silica (core-shell structure), and the use of a type of nanoparticle known as an MXene. These latter particles are a so-called 2D material (like graphene) that can be used to manipulate the roughness (and thus hydrophobicity) of a surface on very fine scales. In all cases, these coatings were created by project members. In particular, the combination of a polypeptide that partially mimics a component of human skin with certain antimicrobial peptides seems highly effective and the project is seeking to obtain a patent for this combination and its application.
In order to assess the larger number of novel materials, the project has developed special semi-quantitative screening tests to determine in high-throughput whether a material may be effective as an antimicrobial coating or not. In addition, the project developed a novel dry-touch transfer method for the assessment of the efficacy of antimicrobial surfaces. This test can evaluate the efficacy under more realistic conditions as compared to current standards. We believe that this test will be extremely useful to the wider community, and may form the basis of future standards.
In order to assess the larger number of novel materials, the project has developed special semi-quantitative screening tests to determine in high-throughput whether a material may be effective as an antimicrobial coating or not. In addition, the project developed a novel dry-touch transfer method for the assessment of the efficacy of antimicrobial surfaces. This test can evaluate the efficacy under more realistic conditions as compared to current standards. We believe that this test will be extremely useful to the wider community, and may form the basis of future standards.